{
int n_normal_preds = 0, n_logical_preds = 0;
struct postfix_elt *elt;
+ int cnt = 0;
list_for_each_entry(elt, &ps->postfix, list) {
- if (elt->op == OP_NONE)
+ if (elt->op == OP_NONE) {
+ cnt++;
continue;
+ }
if (elt->op == OP_AND || elt->op == OP_OR) {
n_logical_preds++;
+ cnt--;
continue;
}
+ if (elt->op != OP_NOT)
+ cnt--;
n_normal_preds++;
+ /* all ops should have operands */
+ if (cnt < 0)
+ break;
}
- if (!n_normal_preds || n_logical_preds >= n_normal_preds) {
+ if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) {
parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
return -EINVAL;
}